Hugh Orde, president of the Association of Chief Police Officers, was named as best suited to be the next Metropolitan police commissioner by a Home Office panel Photograph: Miguel Medina/AFP/Getty Images

An official panel has ranked Sir Hugh Orde as best suited to be the next Metropolitan police commissioner, the Guardian has learned, but his vocal opposition to the government's desire to radically reform policing is expected to cost him the job.

Final interviews for the biggest job in British policing will be held on Monday morning. All four candidates will be questioned by the home secretary, Theresa May, and the London mayor, Boris Johnson. The successful candidate is expected to be announced on Monday afternoon.

David Lammy, MP for Tottenham, told the Guardian that, whoever became commissioner, the most important task they had was to boost the numbers of minority ethnic officers in the force.

The favourite is the Met's acting deputy commissioner, Bernard Hogan-Howe, known to be highly rated by ministers, with Stephen House in second place. House, the chief constable of Strathclyde police, was invited to apply by the Home Office after his force won praise for its work on gangs in Glasgow. The other candidate is the acting Met commissioner, Tim Godwin.

Hogan-Howe, a former head of Merseyside police, was seconded into the force by May after Sir Paul Stephenson was forced out as commissioner over errors of judgment in the phone-hacking case.

On Merseyside, Hogan-Howe was viewed as having performed well tackling gangs and crime, as well as modernising the force. Before his current role, he was working for Her Majesty's Inspectorate of Constabulary.

House has also modernised the force. He is reputed to be in work by 6.30am and a favourite to be the first head of the single Scotland-wide force if he fails to get the Met job.

Hogan-Howe and House have another factor in their favour. Both their tenures in charge of forces outside of London saw a reduction in crime despite working with tighter budgets.

Challenges for the new commissioner include reducing crime despite budget cuts, dealing with politicians

The four candidates have been interviewed twice, by a Home Office panel comprising civil servants and experts and, last Tuesday, by a special panel of the Metropolitan police authority (MPA).

The panel ranked Orde as its number one choice and his rejection risks the government being accused of political interference. It was expected that only the top two candidates would go through to the final round of interviews, but May and Johnson decided to interview all four.

Assessments of the four candidates by Her Majesty's Inspectorate of Constabulary said all were suitable for the job.

Orde is president of the Association of Chief Police Officers and was praised for his role as the first chief constable of the Police Service of Northern Ireland where he had to bridge the sectarian divide.

Godwin, like Orde, is seen to be ill at ease with the government's desire for wholesale changes in policing.

Whitehall sources said the home secretary had every right to decide to personally interview all four candidates as the law states she is responsible for the decision after taking into account recommendations by the MPA and representations from the mayor.

The government, from the prime minister down, believes policing needs radical reform and Orde has publicly criticised them over a number of measures: "He is the chief spokesman for the way things have been, and the government wants to shake things up," a source with knowledge of government thinking said, adding: "What anybody else says, such as the MPA, is not binding on the home secretary."

The last two Scotland Yard commissioners have resigned mid-term and one Whitehall source said: "Orde is not the candidate for a quiet life."

Identifying one major challenge for the successful candidate, Lammy said that policing by consent was no longer possible unless there was a surge in recruitment of black and Asian officers. "The police in London have got to start looking like the police in New York. We have stalled in relation to ethnic minority recruitment. How can you establish consent in this environment?"

Minority ethnic officers represent 9.6% of the force, in a city where at least a quarter are from minority backgrounds.